"It's amazing how kind people are in a situation like this,'' Corcoran said on the 3rd hour of TODAY. "I'm very appreciative."
John Corcoran, 64, died of a heart attack while vacationing with a friend, Gabby Rodriguez, in the Dominican Republic on April 21, the family said.
Barbara Corcoran, 70, said her brother's death was unrelated to the other recent American tourist deaths in the Dominican Republic.
"My brother died there, but he had an existing heart condition, so nothing is related at all, but still it was a tremendous loss,'' she said. "He was a phenomenal brother."
At least nine Americans have died in the Dominican Republic under mysterious circumstances in the past year, including three Americans who died at Bahia Principe resorts over a five-day period in May.
However, the U.S. State Department said it has not seen an uptick in the number of U.S. citizen deaths in the Dominican Republic compared to previous years.
John was a retired owner of a roofing and siding business in Edgewater, New Jersey.
His daughters, Alina and Nichole, wrote in a Facebook post that he was buried in the Dominican Republic in Rodriguez's hometown of Bonao two days after his death.
"We thank you all for your condolences,'' the daughters wrote. "The messages and phone calls that have poured in are a testament to how loved and liked our father was and certainly brings us comfort during this difficult time."
Barbara, who is one of 10 children, first addressed her brother's death in an Instagram post on June 13.
"My brother had an existing heart condition and we believe he died of natural causes, but you're never still ready for the death of a loved one,'' she wrote.
"I'm overwhelmed with sadness for the loss of lives in the DR and my thoughts are with the families who have lost loved ones. Thank you for all your thoughts and good wishes. I appreciate your love and kindness."